Accurate micro-computed tomography imaging of pore spaces in collagen-based scaffold

In this work we have used X-ray micro-computed tomography (μCT) as a method to observe the morphology of 3D porous pure collagen and collagen-composite scaffolds useful in tissue engineering. Two aspects of visualizations were taken into consideration: improvement of the scan and investigation of its sensitivity to the scan parameters. Due to the low material density some parts of collagen scaffolds are invisible in a μCT scan. Therefore, here we present different contrast agents, which increase the contrast of the scanned biopolymeric sample for μCT visualization. The increase of contrast of collagenous scaffolds was performed with ceramic hydroxyapatite microparticles (HAp), silver ions (Ag⁺) and silver nanoparticles (Ag-NPs). Since a relatively small change in imaging parameters (e.g. in 3D volume rendering, threshold value and μCT acquisition conditions) leads to a completely different visualized pattern, we have optimized these parameters to obtain the most realistic picture for visual and qualitative evaluation of the biopolymeric scaffold. Moreover, scaffold images were stereoscopically visualized in order to better see the 3D biopolymer composite scaffold morphology. However, the optimized visualization has some discontinuities in zoomed view, which can be problematic for further analysis of interconnected pores by commonly used numerical methods. Therefore, we applied the locally adaptive method to solve discontinuities issue. The combination of contrast agent and imaging techniques presented in this paper help us to better understand the structure and morphology of the biopolymeric scaffold that is crucial in the design of new biomaterials useful in tissue engineering.     

Hand as hammer: A comprehensive review of biomechanical studies related to occupational hand strikes

A growing number of workers in modern automotive assembly plants are confronted with occupational tasks involving repeated high‐impact hand strikes. Such repetitive physical workloads account for diseases of soft tissues or musculoskeletal disorders in the hand, wrist, or entire upper body. The purpose of this review was to identify and discuss the most pertinent occupational and physiological investigations concerning such hand strikes with particular emphasis on the biomechanical parameters examined. Articles were drawn from four databases to identify publications about occupational hand strikes. First, studies were selected that evaluated hand impact loads measured with the help of force measurement devices. For a deeper understanding of biomechanical factors regarding hand impacts, the scope of the search was extended to include ancillary studies about impacts on wrists or elbows. Overall, 945 abstracts were screened, and five full‐text articles were included in the final review. In addition, 34 ancillary articles about impact stress on the hand–arm complex were discussed because of positive relations between high forces, repetition rates or acceleration, and progressing stress in the hand–arm complex identified in studies about critical biomechanical load limits, in the field of fall arrests and sports, i.e. tennis. Furthermore, studies about effective arm movements and body postures during hand strikes as used in martial arts were reviewed. Although certain biomechanical parameters are both known and well documented, studies available at present cannot sufficiently account for specific disorders in the wrist or arm that are triggered by occupational hand strikes.     

Composition and surface energy characteristics of new petroleum resins

We investigated the composition and surface energy properties—the surface free energy, acid–base and dispersive components, acid and base parameters (according to the van Oss–Chaudhury–Good method) and acidity parameter (according to the Berger method) for several types of aromatic petroleum resins (PR). We could see that the Berger, nonlinear systems, and spatial methods provide slightly different information about the acid–base properties of PRs. For acid–base properties, relevant proton content was determined for each sample by nuclear magnetic resonance spectroscopy. Correlations between the composition and surface characteristics of the studied aromatic PR have been revealed. According to the data obtained from the acid–base approach and nuclear magnetic resonance spectroscopy, we can predict the possible combinations of PR–polymer with the best interface interaction, which can lead to high mechanical properties. POLYM. ENG. SCI., 57:1028–1032, 2017. © 2016 Society of Plastics Engineers     

Quasi‐isothermal DSC testing of epoxy adhesives using initial fast heating rates

Three major factors decrease the accuracy of the cure measurement in standard‐isothermal testing using differential scanning calorimetry (DSC). First, cure occurs during the heating step. Second, data are lost during the stabilization period between the dynamic and isothermal step. Third, the baseline selection requires a modification to the protocol. An alternative, which is explored in this study, is the use of fast ramps, which decrease the heating time, but this has been avoided due to overshoot that occurs between the dynamic and isothermal step, which is troublesome for systems with autocatalytic kinetics. By mitigating these factors, a quasi‐isothermal protocol was developed. Therefore, more complete cure kinetics were captured with the implementation of fast DSC to decrease the ramp time and through the optimization of furnace parameters to decrease stabilization time and temperature overshoot. The data suggested this quasi‐isothermal analysis more accurately measured the isothermal curing kinetics of a commercial epoxy adhesive at 110, 115, and 120 °C for fast ramps of 175, 350, and 500 K/min compared to the traditional ramp of 5 K/min. The enthalpy spike at the dynamic to isothermal transition remains an issue; however, an empirical shift can be used to compensate for the enthalpy signal lag. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45425.     

Die Sterbehilfedebatte und das Bild der Palliativmedizin in deutschen Printmedien

Background In Germany the discussion about euthanasia and physician assisted suicide is prevalent in the media. This study will analyse the way German newspapers represent the discussion about the end of life and how they report about palliative medicine. Methods A qualitative data analysis was performed of 433 articles published in the years 2006 and 2007 in different German newspapers. The archives of the selected newspapers were searched for “palliative medicine”, “hospice”, “patient’s autonomy”, “patient’s will”, “euthanasia” and “terminal care”. Results Dignity, autonomy, inadequate provision of care and uncertainties were identified as the major topics in the debate about euthanasia. Dignity was used both as an argument for and against legislation of euthanasia. The terminology on euthanasia is not used consistently in Germany. Palliative medicine is described as a possible alternative to euthanasia which should be developed and reimbursed better. Conclusion These findings underline the importance of dignity and autonomy for the public opinion on the end of life. The media show the potential of palliative medicine as an alternative to euthanasia but claim further development of palliative care. The inconsistencies in terminology as well as in the content of end of life decisions have to be clarified to allow an objective discussion. Politicians and the medical profession should know about the public statements and opinions, to react adequately to patient’s fears and allowances.     

Superior Magnetic Performance in FePt L10 Nanomaterials

The discovery of the high maximum energy product of 59 MGOe for NdFeB magnets is a breakthrough in the development of permanent magnets with a tremendous impact in many fields of technology. This value is still the world record, for 40 years. This work reports on a reliable and robust route to realize nearly perfectly ordered L1₀‐phase FePt nanoparticles, leading to an unprecedented energy product of 80 MGOe at room temperature. Furthermore, with a 3 nm Au coverage, the magnetic polarization of these nanomagnets can be enhanced by 25% exceeding 1.8 T. This exceptional magnetization and anisotropy is confirmed by using multiple imaging and spectroscopic methods, which reveal highly consistent results. Due to the unprecedented huge energy product, this material can be envisaged as a new advanced basic magnetic component in modern micro and nanosized devices.     

Validation of the ABZ landing gear system using ProB

International Journal on Software Tools for Technology Transfer - In this article, we present our formalization of the ABZ landing gear case study in Event-B. The development was carried out using...     

Power profiling of multimedia sensor node with name-based segment streaming

Multimedia Tools and Applications - Multimedia streaming from miniaturized sensors is attractive for a wide range of web-based applications, including surveillance and Internet of Things (IoT)...